The invention relates to a process for packing bulk materials, especially large-sized lump foods and luxury foods such as (potato) crisps, into packaging containers preferably (tube) bags made of plastic foil. The invention further relates to an apparatus for conducting the process.
The handling of bulk materials of awkward shapes, especially of light-weight potato crisps, creates particular problems in the packaging art. Such bulk materials are a normally packed in tube bags. To apply closure seams to this type of package is particularly problematic. Quite frequently, parts of the material to be packed are still left in the closure portion and thus make it difficult to apply the closure seam by means of thermal welding.
In a known apparatus for packing potato crisps in tube bags, a stripper means is assigned to the sealing means applying the closure seam which is directed transverse to the foil tube. After a process of filling the bag is completed this stripper means is guided on the outside along the packaging foil, that is to say along the foil tube, in the region where the closure seam is to be applied, and thus conducts a stripping movement. In this process, any residues of the material to be packaged are to be removed from the inside of the foil tube in this region. (EP-A-165 819).
When delicate materials, especially awkward-shaped potato crisps, are packed, the stripping movement along the outs side of the foil tube does not remove in a sufficiently reliable manner all residues from the region where the closure seam will be applied. As the residues of the material to be packed are to be removed by mechanical stripper means contacting the foil on the outside, there is a risk of damaging the material to be packed without efficiently stripping it down.